I'm new to directional beam antennas, and saw that K9W Wake Island DXpedition was working 10 meters "long-path" at 1230z, or 6:30a.m. in Texas. This was late enough for the sun to be coming up, but is it even possible to make the "long path" connection that far around? I would have thought Wake Island was totally in the dark at that time. More generally, what is an ideal situation for long path, and is it simply a matter of pointing 180 degrees away from the listed direction on QRZ.com?
You are correct, the long path azimuth is simply 180 from the bearing listed in QRZ.
Whether it's going to work depends on a number of varibles: your power, your antenna, their antenna, the band, atmospheric conditions, the time of day, the terrain on the path and probably a few others I have forgotten.
Doing 10m, a "daytime" band long path to the east at local dawn might work given favorable propigation conditions. And the fact that when 10m is open, it can be really open.
I have never made a long path QSO personally (well, on purpose anyway), but those folks that do work that way seem to be working "diagonally" if you will. For instance, the long path to Europe from Australia is mostly over ocean (salt water being good for this). And don't forget the great circle route is the true route you are looking at here, not the obvious "straight line" paths you see on flat maps.